A gas gas a volume of 4.0 liters at a pressure of 0.80 atm. What is the volume if the pressure is changed to 0.40 atm at a constant temp

The volume is 8,0 L.

Explanation:

We apply Boyle Mariotte's Law: for a given mass of gas at constant temperature, its pressure and volume vary inversely proportionally (the higher the pressure, the lower the volume and vice versa):

P1 x V1 = P2 xV2

V2 = (P1 x V1)/P2

V2 = ( 0,80 atm x 4,0 L)/ 0,40 atm

V2= 8,0 L

answer

the ions in solute supperate from eachouthere

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.